Hail to supportive boyfriends. Mine took excellent care of me during my recovery.
Get some laxative or stool softener. If she's prescribed painkillers, they will cause constipation. Colace, Sennkot, Miralax or the store brand equivalent will all help.
Get a belly pillow and bring it to the hospital with you when you pick her up. Every bump in the road is going to hurt. She'll also want it at home because every cough or sneeze will hurt. I got this one on Amazon well into my recovery and wish I'd gotten it sooner.
If you have an Amazon Alexa, get a smart plug for her bedside lamp. She's not going to want to reach over to turn the lamp on and off.
Get a shower caddy so everything is between shoulder and waist level.
Some people need toilet risers or something to help them get on and off the toilet. I'm lucky that I have a towel bar above my toilet that I could use to help me get up and down. You could get that or some sort of grab bar.
And if you want to get her something cute and funny, you can search on Amazon for hysterectomy gifts.
Best wishes to your girlfriend on a smooth recovery.